There are a number of liquid compositions or diluted mixtures sold in commerce having names such as “activity drinks,” “sports drinks,” “energy drinks,” “nutrient drinks,” and the like. These beverages are advertised to ameliorate physiologic symptoms resulting from the loss of carbohydrates, electrolytes, vitamins, minerals, amino acids, and other important nutrients, during heavy exercise. As those skilled in the art will appreciate, athletic performance, i.e. physical exercise, comprises many different categories of activities, including activities requiring strength, speed, and/or endurance. As those skilled in the art will further appreciate, environmental factors, including temperature, air purity, elevation, humidity, and the like, can markedly affect a person's physical work capacity.
It is thought that muscle activity is primarily based on a very fundamental biochemical mechanism, the breakdown of energy-rich phosphate bonds. Adenosine triphosphate (“ATP”) is one source of such phosphate bonds at the cellular level. ATP is the direct source of energy for muscle work and, some believe, comprises the only form of chemical energy which can be converted by muscle tissue into mechanical work.
During high physical activity of the body, the ATP level in the muscles diminishes rapidly. Several substrates are available as sources for replenishing the ATP. When there is low physical activity, metabolism of fats is primarily responsible for ATP production. At higher activity rates, glycogen in the muscle is the major energy supply. The energy from glycogen is released in exercising muscles up to three times as fast as the energy from fat. It is known in the art that exercise of a moderate intensity cannot be maintained without sufficient carbohydrate stores within the body. Carbohydrates are the fuel from which body cells obtain energy for cellular activities and the major portion of carbohydrates utilized by the body are used for ATP production. The energy required for developing athletic activity, and indeed for all muscular work, comes primarily from the oxidation of glycogen stored in the muscles.
Glycogen can be used either relatively slowly via the complete glycolysis and oxidative phosphorylation to form carbon dioxide, water and 38 moles of ATP per mole of glucose. The basic biochemical pathway being: C6H12O6+6O2→6CO2+6H2O+energy (heat, ATP). This happens not all at once but in many small steps, to control the release of energy. Each step uses one or more enzymes; some use ATP for activation energy. The first process is sometimes called Glycolysis, where, using enzymes, glucose is cleaved into two pieces, and some ATP and NADH are formed. Subsequently, the Krebs cycle transfers electrons, H+ and energy from C—H bonds to NAD+, making NADH. In addition, some ATP is formed. The Krebs cycle occurs in the center of the mitochondrion (inside inner membrane).
Thereafter, an electron transport chain transfers the energy from NADH to produce more than 30 moles of ATP. This happens on the inner membrane of the mitochondrion. Energy is used in small steps to push H+ ions across the membrane. They pile up, then flow through an opening in ATP synthase (an enzyme), where the energy of the flow is used to make ATP.
When exercise is very intensive, i.e. so intensive that the respiratory and cardiovascular systems of the body do not have sufficient time to deliver oxygen to the muscles, the energy for this activity will be delivered almost exclusively from anaerobic metabolism, and much less ATP per molecule of glucose is produced.
Fatigue during high intensity exercise may be viewed as the result of a simple mismatching between the rate at which ATP is utilized and the rate at which ATP is produced in working muscles. The attention, given over the last two decades to the study of the limitations of ATP production, leads to the conclusion that the cause of fatigue may be the inability of the metabolic machinery to provide ATP fast enough for the energy needs of the working muscles to sustain force production.
Furthermore, during relatively extended periods of heavy muscle work, the work capacity of an individual is limited by several factors, such as low blood sugar concentration and loss of liquid by transpiration. In the last decade the use of liquid drinks containing carbohydrates during exercise has become more and more accepted as a stimulus during endurance performance. As a result, the prior art focuses exclusively on ingesting substantial amounts of carbohydrate in a liquid form during endurance competition events. The prior art further teaches that supplementation with carbohydrate containing fluids is useful to prolong exercise and improve the performance of high intensity endurance exercise. Benefits to be obtained include maintenance of fluid balance and an increase in the availability of carbohydrate—the primary substrate for the muscular ATP production.
The present inventor has found, however, that it is not always logistically possible to consume large amounts of carbohydrate-containing beverages over extended periods of time. For example, heavy exercise in remote areas wherein any such beverages must first be carried for long distances prior to consumption renders such a prior art approach non-feasible. Moreover, although considerable amounts of carbohydrates can be ingested, not all of the exogenous carbohydrates emptied from the stomach are oxidized during exercise.
In addition, gastric emptying rate decreases with increasing carbohydrate concentration and osmolality. Consequently highly concentrated carbohydrate solutions have been observed to increase the frequency of gastrointestinal distress in endurance athletes. Certain timing issues can further complicate the consumption of large amounts of carbohydrates. The efficiency of ingested glucose in enhancing physical performance is dependent on the time at which the beverage is ingested before exercise. It is known in the art that glucose containing beverages produce an increase in plasma glucose peaking approximately 45 minutes after ingestion. Such an increase in plasma glucose, however, results in an increase in plasma insulin and a subsequent drop in plasma glucose during the initial period of the activity, resulting in quick exhaustion. Thus, ingestion of large amounts of carbohydrates prior to embarking on a lengthy period of vigorous physical activity in the afore-mentioned remote area scenario can be deleterious rather than advantageous.
Creatine is sometimes used during exercise as a likely substance for the generation (in theory) of ATP through a reaction of phoshocreatine, due to the action of the enzyme creatine kinase (CK). However, administration of creatine can increase the propagation of methanal (formaldehyde). Clinical evaluation of urinalysis indicates insufficient excretion of methanal, leading to the indication of increased formaldehyde cell/tissue saturation as well as nephrotoxicity. Methanal is rarely encountered in living organisms, and when so, converts to formic acid. Formic acid, however, altogether prevents or significantly minimizes the generation of ATP because it induces a diminishing activity of the enzyme complexes within the Krebs cycle. It has been found by the inventor that creatine is disfavorable for the propagation of ATP from ADP and negates pyruvate dehydrogenase's activity.